$stu - 6t + 8u - 4 = -4t + 5u + 8$ Solve for $s$.
Solution: Combine constant terms on the right. $stu - 6t + 8u - {4} = -4t + 5u + {8}$ $stu - 6t + 8u = -4t + 5u + {12}$ Combine $u$ terms on the right. $stu - 6t + {8u} = -4t + {5u} + 12$ $stu - 6t = -4t - {3u} + 12$ Combine $t$ terms on the right. $stu - {6t} = -{4t} - 3u + 12$ $stu = {2t} - 3u + 12$ Isolate $s$ $s{tu} = 2t - 3u + 12$ $s = \dfrac{ 2t - 3u + 12 }{ {tu} }$